xapian-core  1.4.19
Public Member Functions | Private Member Functions | Private Attributes | List of all members
ExactPhrasePostList Class Reference

Postlist which matches an exact phrase using positional information. More...

#include <exactphrasepostlist.h>

+ Inheritance diagram for ExactPhrasePostList:
+ Collaboration diagram for ExactPhrasePostList:

Public Member Functions

 ExactPhrasePostList (PostList *source_, const std::vector< PostList *>::const_iterator &terms_begin, const std::vector< PostList *>::const_iterator &terms_end)
 
 ~ExactPhrasePostList ()
 
Xapian::termcount get_wdf () const
 Return the wdf for the document at the current position. More...
 
Xapian::doccount get_termfreq_est () const
 Get an estimate of the number of documents indexed by this term. More...
 
TermFreqs get_termfreq_est_using_stats (const Xapian::Weight::Internal &stats) const
 Get an estimate for the termfreq and reltermfreq, given the stats. More...
 
std::string get_description () const
 Return a string description of this object. More...
 
- Public Member Functions inherited from SelectPostList
PostListnext (double w_min)
 Advance the current position to the next document in the postlist. More...
 
PostListskip_to (Xapian::docid did, double w_min)
 Skip forward to the specified docid. More...
 
PostListcheck (Xapian::docid did, double w_min, bool &valid)
 Check if the specified docid occurs in this postlist. More...
 
Xapian::doccount get_termfreq_max () const
 Get an upper bound on the number of documents indexed by this term. More...
 
Xapian::doccount get_termfreq_min () const
 Get a lower bound on the number of documents indexed by this term. More...
 
double get_maxweight () const
 Return an upper bound on what get_weight() can return. More...
 
Xapian::docid get_docid () const
 Return the current docid. More...
 
double get_weight () const
 Return the weight contribution for the current position. More...
 
Xapian::termcount get_doclength () const
 Return the length of current document. More...
 
Xapian::termcount get_unique_terms () const
 Return the number of unique terms in the current document. More...
 
double recalc_maxweight ()
 Recalculate the upper bound on what get_weight() can return. More...
 
PositionListread_position_list ()
 Read the position list for the term in the current document and return a pointer to it (owned by the PostList). More...
 
PositionListopen_position_list () const
 Read the position list for the term in the current document and return a pointer to it (not owned by the PostList). More...
 
bool at_end () const
 Return true if the current position is past the last entry in this list. More...
 
Xapian::termcount count_matching_subqs () const
 Count the number of leaf subqueries which match at the current position. More...
 
std::string get_description () const
 Return a string description of this object. More...
 
 SelectPostList (PostList *source_)
 
 ~SelectPostList ()
 
- Public Member Functions inherited from Xapian::PostingIterator::Internal
virtual ~Internal ()
 We have virtual methods and want to be able to delete derived classes using a pointer to the base class, so we need a virtual destructor. More...
 
virtual const std::string * get_sort_key () const
 
virtual const std::string * get_collapse_key () const
 If the collapse key is already known, return it. More...
 
Internalnext ()
 Advance the current position to the next document in the postlist. More...
 
Internalskip_to (Xapian::docid did)
 Skip forward to the specified docid. More...
 
virtual void gather_position_lists (OrPositionList *orposlist)
 Gather PositionList* objects for a subtree. More...
 
- Public Member Functions inherited from Xapian::Internal::intrusive_base
 intrusive_base ()
 Construct with no references. More...
 

Private Member Functions

void start_position_list (unsigned i)
 Start reading from the i-th position list. More...
 
bool test_doc ()
 Test if the current document contains the terms as an exact phrase. More...
 

Private Attributes

std::vector< PostList * > terms
 
PositionList ** poslists
 
unsigned * order
 

Additional Inherited Members

- Public Attributes inherited from Xapian::Internal::intrusive_base
unsigned _refs
 Reference count. More...
 
- Protected Member Functions inherited from Xapian::PostingIterator::Internal
 Internal ()
 Only constructable as a base class for derived classes. More...
 
- Protected Attributes inherited from SelectPostList
PostListsource
 
double wt
 

Detailed Description

Postlist which matches an exact phrase using positional information.

ExactPhrasePostList only returns a posting for documents contains all the terms (this part is implemented using an AndPostList) and additionally the terms occur somewhere in the document in the order given and at adjacent term positions.

The weight of a posting is the sum of the weights of the sub-postings (just like an AndPostList).

Definition at line 38 of file exactphrasepostlist.h.

Constructor & Destructor Documentation

◆ ExactPhrasePostList()

ExactPhrasePostList::ExactPhrasePostList ( PostList source_,
const std::vector< PostList *>::const_iterator &  terms_begin,
const std::vector< PostList *>::const_iterator &  terms_end 
)

Definition at line 34 of file exactphrasepostlist.cc.

References Assert, order, poslists, and terms.

◆ ~ExactPhrasePostList()

ExactPhrasePostList::~ExactPhrasePostList ( )

Definition at line 51 of file exactphrasepostlist.cc.

References order, and poslists.

Member Function Documentation

◆ get_description()

string ExactPhrasePostList::get_description ( ) const
virtual

Return a string description of this object.

Implements Xapian::PostingIterator::Internal.

Definition at line 175 of file exactphrasepostlist.cc.

References Xapian::PostingIterator::Internal::get_description(), and SelectPostList::source.

◆ get_termfreq_est()

Xapian::doccount ExactPhrasePostList::get_termfreq_est ( ) const
virtual

Get an estimate of the number of documents indexed by this term.

It should always be true that: get_termfreq_min() <= get_termfreq_est() <= get_termfreq_max()

Implements Xapian::PostingIterator::Internal.

Definition at line 148 of file exactphrasepostlist.cc.

References Xapian::PostingIterator::Internal::get_termfreq_est(), and SelectPostList::source.

◆ get_termfreq_est_using_stats()

TermFreqs ExactPhrasePostList::get_termfreq_est_using_stats ( const Xapian::Weight::Internal stats) const
virtual

Get an estimate for the termfreq and reltermfreq, given the stats.

The frequencies may be for a combination of databases, or for just the relevant documents, so the results need not lie in the bounds given by get_termfreq_min() and get_termfreq_max().

Reimplemented from Xapian::PostingIterator::Internal.

Definition at line 162 of file exactphrasepostlist.cc.

References Xapian::PostingIterator::Internal::get_termfreq_est_using_stats(), LOGCALL, RETURN, SelectPostList::source, and TermFreqs::termfreq.

◆ get_wdf()

Xapian::termcount ExactPhrasePostList::get_wdf ( ) const
virtual

Return the wdf for the document at the current position.

The default implementation throws Xapian::UnimplementedError.

Reimplemented from Xapian::PostingIterator::Internal.

Definition at line 133 of file exactphrasepostlist.cc.

References terms.

◆ start_position_list()

void ExactPhrasePostList::start_position_list ( unsigned  i)
private

Start reading from the i-th position list.

Definition at line 58 of file exactphrasepostlist.cc.

References order, poslists, and terms.

Referenced by test_doc().

◆ test_doc()

bool ExactPhrasePostList::test_doc ( )
privatevirtual

Test if the current document contains the terms as an exact phrase.

Implements SelectPostList.

Definition at line 75 of file exactphrasepostlist.cc.

References Xapian::PositionIterator::Internal::get_position(), LOGCALL, order, poslists, RETURN, SelectPostList::skip_to(), start_position_list(), and terms.

Member Data Documentation

◆ order

unsigned* ExactPhrasePostList::order
private

◆ poslists

PositionList** ExactPhrasePostList::poslists
private

◆ terms

std::vector<PostList*> ExactPhrasePostList::terms
private

Definition at line 39 of file exactphrasepostlist.h.

Referenced by ExactPhrasePostList(), get_wdf(), start_position_list(), and test_doc().


The documentation for this class was generated from the following files: